Question about per-pixel temperature and emissivity input for TOA radiance simulation in DART

[jones James]

Dear DART Team,

I hope this message finds you well.

I am currently working on thermal simulation using DART, with the goal of obtaining top-of-atmosphere (TOA) radiance and brightness temperature.

According to my understanding, this requires assigning both temperature and emissivity to each pixel in the scene. At present, I have defined temperature using a single-layer 3D temperature file. However, I have not been able to identify the correct method to input emissivity.

Using my current setup, the simulated brightness temperature is consistently lower than expected physical values.

To better understand this issue, I searched the DART forum and found discussions suggesting that both temperature and emissivity should be provided per pixel through an XML file. However, I also noticed that some users seem to use TXT-based temperature inputs, which makes the correct workflow unclear to me.

Therefore, I am currently facing two main questions:

1. What is the correct and recommended way to assign both temperature and emissivity at the pixel level in DART?
2. Could the abnormally low brightness temperature be caused by incorrect temperature or emissivity input?

I will attach my project files for your reference.

Thank you very much for your time and support. I would greatly appreciate any guidance you can provide.

Best regards,
Gao Jinran